Clinical outcomes of single open-door posterior decompression with instrumented in situ fusion for cervical ossification ofposterior longitudinal ligament

Objective To evaluate the clinical outcomes of K-line(-) ossification of posterior longitudinal ligament (OPLL) between single open-door posterior decompression with instrumented in situ fusion(PDF) and laminoplasty (LMP). Methods From February 2008 to February 2015, 38 cases including 30 males and 8 females underwent posterior decompression due to K-line(-) OPLL in our institution. The age ranged from 48 to 76 years, mean 56.3±9.7 years. The OPLL canal occupation ratio ranged from 38.6% to 72.5%, mean 58.1%±13.6%. According to surgical procedures, 26 cases were in PDF group and 12 cases were in LMP group. The data collected from both groups included complications, C2-C7 Cobb angle and neurologic symptoms eval-uated based on the Japanese Orthopedic Association (JOA) score and JOA score recovery rate, and were analyzed with statistics in and between groups. Results All the patients were completed follow up with a mean of 3.6±2.1 years (range, 2.5 to 7.0 months). At the final follow-up, the postoperative JOA score was 11.8±1.9 points on average, improved from preoperative 7.7±1.6 points (t=3.757, P 0.05), however, there were significant differences in the postoperative JOA score (t=3.941, P 0.05). On the contrary, the C2-C7 Cobb angle was-2.1°±1.8°, lower than preoperative 3.9°±1.2° (t=6.824, P 0.05), respectively. Conclusion Compared with LMP, PDF without correcting cervical alignment for pa-tients with K-line(-) OPLL showed better neurological recovery and clinical efficacy. Key words: Cervical vertebrae; Ossification of posterior longitudinal ligament; Decompression, surgical; Spinal fusion